ISSN:
1365-3059
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Acibenzolar-S-methyl (ASM), a member of the benzothiadiazoles (BTH), was tested on cauliflower (Brassica oleracea var. botrytis) seedlings for its ability to induce resistance against downy mildew (Peronospora parasitica). Seven-day-old seedlings of the susceptible cultivar Billabong, sprayed with solutions containing 0·015 or 0·075 mg a.i. mL−1 ASM and inoculated 1–8 days later with P. parasitica, were assessed for disease 7 days after inoculation. Sporulation was reduced by 50% at the highest dose of ASM in plants inoculated 1 day later, with complete protection exhibited by plants inoculated 2 days after ASM treatment. Seedlings treated with 0·05 mg a.i. mL−1 ASM solution, inoculated 4 days later and harvested 0–7 days later, were analysed for pathogenesis-related (PR) proteins, chitinase and β-1,3 glucanase. ASM significantly induced β-1,3 glucanase activity which increased with time in inoculated seedlings, as confirmed by the presence of PR-2. Chitinase activity was not significantly induced by ASM, and the treated seedlings also did not accumulate the basic PR-3C and the acidic PR-3Q which both exhibit chitinase activity. Analysis of three other acidic (PR-1C, PR-5S, PR-8) and one basic (PR-6) PR proteins in the ASM-treated seedlings showed that only PR-1 and PR-5 were slightly and slowly induced (4–5 days after treatment), but this induction was more pronounced after inoculation with P. parasitica.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1365-3059.2001.00609.x
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